? Wow, that’s great longevity.
Since gasoline outboards like to run at, or near, wide-open-throttle (WOT), I’m not certain I see much value in a tachometer.
Can I rightly presume that there is nothing presently connected to the (3) aforementioned wires?
I’m not familiar with Izzuzu outboards, so cannot comment on how to add a tachometer - but “Grey” is the current
N. American standard colour for Tach’ sender/sensor to display instrument. Check with an Izuzu dealer.
It used to be that fuel flow gauges, such as ‘FloScan’, didn’t work well at consumption
rates if less than about 1.5 US Gallons per hour; which I’d hope is less than your 25HP engine
consumes. Not certain about some of the newer (and cheaper) units from Lowrance et al. Since most outboards operate from portable day tanks
, which are easy to monitor
, I’d not be inclined to bother with a remote
fuel gauge, never mind a flow meter.
Perhaps others could be more helpful than I ...